Well, I'm interested! Enough to ask if anyone who really knows can tell me what are the absolute certain signs of a genuine Wartsila helmet. Its always possible that the little red decal (or is a a label or a sticker - I have never seen one in the steel) can be erased by accident or design - is the real significant mark the size number followed by a W stamped on the rim? And does that specific mark exist only on the M40 and not the M62?
Also, as I understand it, the original issue had a simple two piece leather strap with no chincup - is that correct?
I find it hard to believe that so many were dumped after WW2 - particularly when the Finns continued using remaining stocks of German helmets (and bought more postwar, come to that). I can't believe they deliberately destoyed their own design helmet (OK, Swedish design helmet, but you see what I mean. made in Finland anyway and still a good design.)
I have a couple of what I believe to be Finnish shells, the later M62, though one may be a actual Swedish M37 type, both with much later liners and straps. The UN-blue obscures any possible sight of any stamping unless I start scraping it off the rim edges. I've had a bit of a struggle understanding these helmets for some time - I wouldn't be totally surprised to find they were both Swedish, though I did buy them from a man in Finland!
I must admit I borrowed the image of the interior of the first helmet from Joseba's website as I don't seem have a pic of my own on file. Its also worth noting that the rivet heads showing on the sides are actually different on each helmets - the first has four apparently flat but actually slightly rounded rivets fore and aft, with definately rounded - and smaller - rivets for the chinstrap, where the second helmet has six identical larger flatter rivets plus one different (same size but more obviously round headed) for the third leg of the three-point chinstrap.